In this study, the possible oxidative stress that water pollution may cause to Asellus aquaticus is evaluated using the physico-chemical parameters, the heavy metal concentration in the water, and organism and biochemical responses in the living organisms being combined together. For this purpose, the A. aquaticus samples are collected by choosing three stations along the Saricay Creek, some of whose regions are exposed to domestic and industrial pollution. Sampling stations are chosen from regions that are interpreted as polluted or clean according to the heavy metal content and physico-chemical parameters where the A. aquaticus individuals live. After the determination of species is performed, the heavy metal (Cu, Fe, Cd, Pb, and Zn) and biomarker (Na+/K+-ATPase, Glutathione, and TBARS) analyzes were made. According to the water quality analysis, S3 was the most polluted station, S2 was a moderately polluted station, and Si was determined as a clean station. A considerable increase in the amount of glutathione (GSH) was detected in the S2 and S3 stations in parallel with the increase of pollution. However, there were no statistical differences in the TBARS levels as an indicator of lipid peroxidation and Na+/K+-ATPase enzyme activity. The significant increase (three-fold) of the GSH levels in the polluted areas indicates that water pollution causes oxidative stress in the A. aquaticus species. These results show that ecological, physico-chemical, and biochemical parameters can be used together to identify and evaluate the water pollution in rivers that are exposed to pollution.